GB1058071A - Improvements in guns having servo-controlled firing mechanisms - Google Patents

Abstract

1,058,071. Firing mechanisms. BREVETS AERO-MECANIQUES S.A. March 10, 1965 [March 17, 1964], No. 10242/65. Heading F3C. An automatic gun having a reciprocating breech block 4 in a reciprocating casing 3 is provided with a servo-trigger mechanism including a spring-type energy accumulator 18 which is periodically loaded by a slide 17 through a pivoted lever 21 connected thereto, the lever 21 being pivoted to load the spring each time the casing 3 recoils through the engagement of the roller 24 on one end of lever 21 with the surface 25 of the casing. Locking means is provided to hold the accumulator fully loaded and comprises an abutment lever 26 which biased by spring 28 moves behind an abutment 17a on the slide 17 when the latter is in its forward position, the lever 26 being held in locking position by a lever 29 pivoted at 30 and biased by spring 31. The lever 29 may be moved so as to permit the lever 26 to rise and release the slide by a spring- loaded pawl 32 pivoted on one arm of a bellcrank lever 34 pivoted at 30 and connected by links 35a to the trigger 35. When the slide 17 is released it moves to the right to strike the end of a balance lever 19 the end of which is held opposite the slide 17 by the end of a pivoted lever 42 actuated by the links 35a engaging the surface 19c. Lever 19 is pivoted at 20 to a bell-crank lever 15 and so when the end of lever 19 is struck by the slide 17 the lever 15 pivots anti-clockwise to permit a roller 12 on a pivoted bent lever 9 to move from surface 15a to surface 15b under the action of a spring 13. The pivoted movement of the lever 9 causes a sear 5a engaged in a notch 4a of the breech block to move downward to release the breech block. When the casing 3 recoils the spring 18 is stressed and the slide 17 locked in its forward position as long as the trigger is kept depressed to continue firing and also when the trigger is released. If the gun is required to fire single shots a rod 44 is pushed towards the left so that a projection 39a on a hook 39 is retracted and ceases to co-operate with holding lug 19a and so permits after the firing of a shot lever 15 to pivot and sear 5 to return to its position in which it retains the breech block in the rear position. The gun may be initially cocked by a cable means which acts on the breech block to move it rearwardly and on levers to stress the spring 18.